$$\mathrm{K_2Cr_2O_7}$$ paper acidified with dilute $$\mathrm{H_2SO_4}$$ turns green when exposed to :

Which will undergo deprotonation most readily in the basic medium?

Which of the following cannot be explained by crystal field theory?

Given below are two statements:

Statement I : Pure Aniline and other arylamines are usually colourless.

Statement II : Arylamines get coloured on storage due to atmospheric reduction.

In the light of the above statements, choose the most appropriate answer from the options given below :